Method and casting mold, in particular for use in cold casting methods

1. A method comprising the steps of:

producing a casting molds for use in cold casting methods at temperatures where the casting mold is not destroyed, wherein the casting mold is built with the aid of a powder-based layering method and has a porous molded body,

treating a porous surface of the casting mold with a sealant which closes pores of the molded body and seals the surface water-tight,

cold casting a part at a temperature where the casting mold is not destroyed, and

removing the part from the casting mold;

wherein the layering method is a powder bed-based 3D printing method and includes:

applying a powder-based layer using a coater, wherein the powder-based layer includes a particle precoated with an activator; and

selectively printing a fluid on the powder-based layer with a print head.

2. The method of claim 1 , wherein the porosity of the surface is modified by an epoxy resin, a polyurethane, an unsaturated polyester, a phenol/resol resin, an acrylate and/or a polystyrene.

3. The method of claim 1 , wherein the porous surface is modified by a black wash or dispersion prior to the step of treating with a sealant, wherein the black wash includes a zirconium oxide, aluminum oxide-, calcium oxide-, titanium oxide-, chalk- or silicic acid-based black wash and the dispersion includes a plastic, cellulose, sugar-, flour and/or salt-based solution.

4. The method of claim 1 , wherein the porosity of the sealant includes a grease, an oil, a wax, or a hot water-soluble substance.

5. The method of claim 1 , wherein a cold resin binding system is used for the layering method.

6. The method of claim 5 , wherein the surface is sealed with a hydrophobic material.

7. The method of claim 5 , wherein the porosity of the surface is modified by an infiltrate prior to the step of treating with a sealant.

8. The method of claim 5 , wherein the porosity of the surface is modified by an epoxy resin, a polyurethane, an unsaturated polyester, a phenol/resol resin, an acrylate and/or a polystyrene.

9. The method of claim 5 , wherein the porosity of the surface is modified by a zirconium oxide-, aluminum oxide-, calcium oxide-, titanium oxide-, chalk- or silicic acid-based black wash prior to the step of treating with a sealant.

10. The method of claim 5 , wherein the porosity of the surface is modified or sealed by means of a hot water-soluble substance.

11. The method of claim 1 , wherein the cold casting methods is for producing a concrete cast part.

12. The method of claim 1 , wherein the cold casting method is for producing a cold-cast polymer component.

13. The method of claim 1 , wherein the

particle is a sand particle.

14. The method of claim 13 , wherein the fluid reacts with the activator on the powder-based layer to form a polymer that binds the sand particles together.

15. A method comprising the steps of:

producing a casting molds for use in cold casting methods at temperatures where the casting mold is not destroyed, wherein the casting mold is built with the aid of a powder-based layering method,

treating a porous surface of the casting mold,

cold casting a part at a temperature where the casting mold is not destroyed, and

removing the part from the casting mold;

wherein the layering method includes applying a powder-based layer using a coater,

wherein the powder-based layer includes a sand particle precoated with an activator; and

selectively printing a fluid on the powder-based layer with an ink jet print head;

wherein the fluid reacts with the activator on the powder-based layer to form a polymer that binds the sand particles together.

16. The method of claim 15 , wherein the casting mold includes a surface modified by an epoxy resin, a polyurethane, an unsaturated polyester, a phenol/resol resin, an acrylate, or a polystyrene, for reducing the porosity of the surface.

17. The method of claim 15 , wherein the casting mold includes a surface modified by a black wash or a dispersion, for reducing the porosity of the surface, wherein the black wash includes a zirconium oxide, aluminum oxide, calcium oxide, titanium oxide, a chalk, or a silicic acid, and the dispersion includes a plastic, a cellulose, sugar, flour, or a salt.